Out of the 203 million people who used the web in the United States last month, more than 116 million were on Facebook, according to Nielsen. That’s a 5.8% percent increase over what it reported in December, and roughly on track with the growth rates it and rival firms have been seeing lately.

The more interesting part is how much more time people are spending on Facebook versus other sites.

Most users on other properties owned by the 10 largest web companies on the web saw an average of, at the most 2 hours a month. Facebook’s users spent 7 hours on the site, on average. That’s not all. The average time spent on all of the other top 10 properties fell versus the previous month, but Facebook’s rose by 9.7%. Nielsen has divided up its top 10 rankings by both the top “parent companies/divisions” on the US web — the stats, above — but it has also broken out rankings by individual sites. The same trends are clearly visible, either way.

Another interesting point here. Facebook’s latest self-reported statistics say that the average user spends 55 minutes a day on the site, which implies nearly 30 hours a month. That average includes Facebook’s international traffic, which comprises more than 70% of its 400 million monthly active users, it says. So perhaps US users have typically spent a lot less time than their international peers on Facebook, but are starting to spend more time now?

However, it’s not as if Facebook is taking over everything on the web, though. Its service intends to keep people engaging with it as much as possible, doing things like looking at photos and using applications. Other major internet properties, like Google’s search engine, are intended to help people find other sites they’re looking for as quickly as possible. Many of the others on the list also have more utilitarian purposes. A more significant way to look at this traffic is by the amount of money it generates — on that front, Facebook still has a lot of growing to do.